Social interaction is a dynamic, changing sequence of social actions between individuals (or groups) who modify their actions and reactions due to the actions by their interaction partner(s). In other words they are events in which people attach meaning to a situation, interpret what others are meaning, and respond accordingly.

Social interactions can be differentiated into:

accidental (also known as social contact) - not planned and likely not repeated. For example, asking a stranger for directions or shopkeeper for product availability.

repeated - not planned, bound to happen from time to time. For example, accidentally meeting a neighbour from time to time when walking on your street;

regular - not planned, but very common, likely to raise questions when missed. Meeting a doorman or a security guard every workday in your workplace, dining every day in the same restaurant, etc.